Transient control of serum cholesterol homeostasis in adult ExHC (exogenous hypercholesterolemic) rats by dietary cholesterol during weanling period.

Rats hyper-responsive to a diet containing cholesterol plus cholic acid (exogenous hypercholesterolemic (ExHC) rats) were used to assess if cholesterol feeding at weanling period influences later serum cholesterol homeostasis. Diets containing cholesterol plus cholic acid (atherogenic diet) in early life, when compared to non-atherogenic diet, caused a transient suppression of serum cholesterol elevation in very-low- and low-density lipoprotein fractions during refeeding of the atherogenic diet in later life. Such an effect was not observed when ExHC rats were early given a diet supplemented with cholesterol or cholic acid alone, nor when ordinary Sprague-Dawley rats were given atherogenic diet. Early atherogenic diet caused an increased secretion of cholesterol as very-low-density lipoprotein from the perfused livers of adult ExHC rats. Neither the activity of hepatic cholesterol-7 alpha-hydroxylase of fecal steroid excretion in later life was influenced by the early dietary manipulation. Therefore, the present results show the deferred effect of early dietary manipulation on later serum cholesterol metabolism in ExHC rats, but the underlying mechanism(s) remains to be determined.